What this breaker does for your panel
The Siemens 3RV1341-4FC10 is a SIRIUS circuit breaker designed specifically for starter combinations — meaning it's built to sit ahead of a contactor, protecting the motor branch from short circuits and overloads in one compact package. Rated 40 A continuous with a 50 kA breaking capacity at 400 V AC, it handles fault currents that would vaporize a standard industrial MCB. That 50 kA number is the SCCR at 400 V — if your panel's available fault current is under that, this breaker clears the fault without upstream devices needing to trip, keeping selectivity in your distribution. It's also rated for motor duty at 18.5 kW at 400 V AC-3, so it's a direct fit for a 25 hp (roughly) induction motor on a conveyor or pump. The 15 operations per hour max at AC-3 tells you this isn't for frequent jogging — it's a branch-circuit protector, not a switching device.
Mounting and wiring
Snap-on mounting onto 35 mm DIN rail per EN 50022, any position. Zero clearance needed at the sides or back — you can pack these tight on the rail. The IP20 front means it's finger-safe once installed in an enclosure; the terminals are screw-type with box terminals for the main circuit and separate screw terminals for the aux/control circuit. Wire sizes: solid up to 2x 16 mm², stranded up to 2x 50 mm² (or 1x 70 mm²). That's heavy enough for the 40 A feed. The auxiliary switch option is built in — you can add a signal contact for remote status without extra enclosure space.